Existing transport aircraft use multiple slotted trailing edge wing flaps. The operating mechanism for such flap arrays requires the use of external fairings on the lower wing surfaces. These fairings cause major drag forces during flaps-up operation which penalizes the aircrafts operating economy. An example of an existing multiple slotted wing flap mechanism is disclosed by U.S. Pat. No. 3,853,289, granted Dec. 10, 1974, to Carroll H. Nevermann and Ellis J. Roscow.
Where full span trailing edge wing flaps are used it is convenient to employ the outboard flap segments in a dual mode of motion so that these surfaces can be used as Fowler flaps and also as low speed ailerons.
Flap segment hinge points and flap track or linkage devices mounted below the lower wing skin are two schemes in common use to implement the suspension of multi-segment Fowler type flaps with large deflection angle capability. These devices although useful for flap suspension, do not facilitate the use of the rearward trailing edge flap element as an aileron.
Fowler flaps do not merely rotate relative to the wing body about a hinge connection. They move between a retracted position in which they are a part of the wing and an extended position in which they are both spaced from and at an angle with respect to the wing body. A Fowler flap which could also function as an aileron would have to have the ability to rotate about a pivot axis at each of its flap positions.
Examples of single slotted flap mechanisms are disclosed by the following U.S. patents: U.S. Pat. No. 2,158,676, granted May 16, 1939, to Lloyd F. Englehardt; U.S. Pat. No. 2,352,074, granted June 20, 1944, to Dayton T. Brown and Charles G. Layman; U.S. Pat. No. 2,373,365, granted Apr. 10, 1945, to A. Harold Westberg; U.S. Pat. No. 2,445,833, granted July 27, 1948, to Robert W. Kraemer, Thomas C. Hill and Willem D. van Zelm; U.S. Pat. No. 2,479,619, granted Aug. 23, 1949, to Lewis M. Hilton and Herbert E. Chaplin; U.S. Pat. No. 2,501,726, granted Mar. 28, 1950, to Thomas Knox; U.S. Pat. No. 2,516,406, granted July 25, 1950, to Edward L. Moyer; and U.S. Pat. No. 2,563,453, granted Aug. 7, 1951, to Paul Briend.
Examples of multiple slotted trailing edge wing flaps which may be found in the patent literature are shown by the following U.S. patents: U.S. Pat. No. 2,222,435, granted Nov. 19, 1940, to Joseph Ksoll; U.S. Pat. No. 2,276,688, granted Mar. 17, 1942, to Emile J. E. Dewoitine; U.S. Pat. No. 2,289,704, granted July 14, 1942, to Charles H. Grant; U.S. Pat. No. 3,853,289, granted Dec. 10, 1974, to Carroll H. Nevermann and Ellis J. Roscow; U.S. Pat. No. 3,985,319, granted Oct. 12, 1976, to Roy D. Dean and Richard H. Weiland and U.S. Pat. No. 4,248,395, granted Feb. 3, 1981, to James B. Cole.